Upgrade vboot_reference to 24fd715c90e89df1a90191c8ee1d3d78a29af758

This project was upgraded with external_updater.
Usage: tools/external_updater/updater.sh update external/vboot_reference
For more info, check https://cs.android.com/android/platform/superproject/main/+/main:tools/external_updater/README.md

Test: TreeHugger
Change-Id: Idb0c32f522d38a8809aa48092176572e6251eb20